At the present time, various techniques are used to extract varices in a varicose blood transporting vein, for example the long saphenous vein.
The treatment of varices further makes use of various techniques, including "stripping". This technique is used when a vein segment is pathological and irretrievably damaged. When this segment is short, stripping can be carried out with visual monitoring, after the vein segment to be removed has been completely exposed.
When the segment is long, stripping has to be carried out in a different way using a "semi-blind" technique, which involves stripping the majority of the vein segment without visual monitoring, the latter being possible only in the area of its proximal and distal ends, by means of a short incision allowing the vein to be identified, dissected and catheterized, either downwards or upwards, using instruments.
For this purpose, there is known, in particular, the so-called "exo-stripping" technique, which consists in extracting a section of vein by stripping it away with the use of an instrument that comprises a flexible wire one of the ends of which has a cone shape and the other end of which has an olive shaped member.
Using such an instrument, the surgeon, when removing varices from a leg, bares the vein below the location of the hernia and introduces the bullet shaped end so as to cause the said end substantially to pass the area of the hernia to be extracted. When this introduction operation is carried out, the vein is engaged by the olive shaped member, the diameter of which is far greater than that of the vein. The vein section is then removed by the surgeon, who pulls on the instrument, causing it to emerge in the area of second incision made in the patient's leg.
Such techniques have many drawbacks, in practice, in particular that of necessitating two incisions, on one hand, when the instrument is introduced and, on the other hand, when it is removed.
Furthermore, such instruments are not always suitable for enabling relatively long sections of vein to be extracted, as this may necessitate a large number of incisions, which can be prejudicial to the patient.
It should also be noted that the use of such surgical instruments can give rise to traumatisms of the saphenous vein which result, furthermore, from the surgeon's pulling on the vein and/or the large number of incisions required for such operations.
There is also known the so-called "internal stripping" technique, which consists in removing the vein from the leg by stripping it off using a cable that has been previously inserted inside it. In addition, using this technique, the surgeon extracts a section of vein from the living tissue through which it passes it by causing it to slide gradually against the said tissue, and by exerting an action so that the end of the said section folds longitudinally.
In this technique, the vein is folded back on itself in order to reduce peri-veinous traumatism. The olive shaped member used in "exo-stripping" and having a diameter greater than that of the vein is replaced, here, either by a simple wire joining the cable, to which it is tied during the operation, on the end of the vein to be folded back on itself, or by an intermediate device connecting two cables by means of their respective ends adapted to be interconnected, in particular by snap fastening, and thus to permit stripping, in an alternating movement, of the vein, which has been previously joined to the cable by a strong ligature, pressing in front of or behind this connection according to the direction of traction.
Thus, the instruments used in phlebectomy by catheterism presently known include a long, flexible body such as a cable, for example, the terminal portions of which have a bulge or excrescence further permitting the installation of a pulling handle and/or a means of blocking the vein to be extracted.
These blocking means are, moreover, generally constituted by an element having a diameter at least equal to diameter of the terminal portion of the vein section to be extracted, and complementary shapes and means permitting its stowage and its installation on the excrescences of the said cable.
Now, in practice, such blocking means have numerous drawbacks and, in particular, they are not always easy to use. Furthermore, owing to their diameter, which is at least equal to the outside diameter of the conduit, the tissues are observed to be scraped during removal of the vein to be extracted, which gives rise to injuries and/or physiological traumatisms of the tissues which can be prejudicial to the patient.
Furthermore, the different nerves that are located adjacent to the saphenous vein are liable to be injured when such instruments are used, which makes such operations painful for the patient.
In addition, in practice, although more convenient to use, such devices do not give complete satisfaction as they do not always allow the vein section to be extracted to be held efficiently.
The object of the present invention is to remedy the drawbacks of the instruments designed, in particular, to permit the extraction of vein sections by providing an instrument that can be used to implement -endo and/or exo vein stripping techniques without risk to the patient.
Another object achieved by the instrument according to the invention resides in the fact that it is of simple, robust design, which increases its potential applications.
Another advantage of the instrument according to the invention resides in the fact that it is produced from materials having appropriate characteristics in conformity with the standards in force for such uses, in particular in the field of surgery.
Other objects and advantages of the present invention will emerge in the course of the following description, which is provided, however, only by way of illustration, and is not intended to limit same.